The power control of code division multiple address communication system
The present invention relates to code division multiple access (CDMA) communication system, the particularly power of cdma communication system control.
Existing C DMA tentative standard (to call " IS-95 " in the following text) is formulated by TIA (telecommunications industry association) and EIA (Electronic Industries Association).In IS-95,, send discontinuous (demblee form) signal when the transmission rate of using during less than full rate.This signal is divided into a plurality of 20 milliseconds of long logical frame.These frame segmentations become 16 the littler parts (that is time slot) that are called " power control group ".Base-station demodulator is estimated from the energy of each power control group of mobile radio station reception.If this energy is higher than a threshold value (E
s), then a power control signal will be beamed back to mobile radio station in the base station, make mobile radio station reduce grade of its transmitted power.If this energy is lower than E
s, then this power control signal military order mobile radio station increases grade of its transmitted power.For the full rate transmission, each power control group all is used, and does not have what problem.
Problem takes place when the transmission rate of non-full rate such as 1/4 speed.At present, 1/4 speed rates only 1/4 (that is, 4) in power control group sends, and is irrelevant with the content of the current transmission that is sent in 12 power control groups being left.Yet the energy of the power control group that is not used is still measured.This measurement causes from the base station to the transmission power in mobile station control signal.Current, owing to monitoring which power control group has been used and the energy measurement ignored by the power control group that is not used causes the delivering power control command to be responsible for by mobile radio station.
Because the speed of current system transmissions signal is not full rate, so used the duty cycle (burst duty cycle) (promptly not using all time slots in the frame) of burst, again because a threshold power level is only arranged, so read accurately in order to have one, each real pulse train of sending out must satisfy and the identical E of continuous full rate transmission
sThreshold value.
Fig. 1 illustrates the block diagram of the CDMA reverse channel architecture of prior art;
The matrix of a kind of power control group of dividing according to transmission rate that Fig. 2 illustrates prior art;
Fig. 3 illustrates the block diagram of a kind of CDMA forward channel of prior art;
Fig. 4 illustrates the flow chart of the prior art power control process of a kind of prior art base station;
Fig. 5 illustrates a kind of flow chart of power control process of prior art mobile radio station;
Fig. 6 illustrates the matrix of a kind of power control group of dividing according to transmission rate of being used by the present invention;
Fig. 7 illustrates the flow chart that uses a kind of base station power control procedure of the present invention;
Fig. 8 illustrates the flow chart that uses a kind of transmitting power of mobile station control procedure of the present invention;
Fig. 9 illustrates a kind of being designed to be can use block diagram of the present invention, the CDMA reverse channel architecture;
Figure 10 illustrates the block diagram of the logical structure of a kind of CDMA forward letter;
Figure 11 illustrates the flow chart that uses another kind of transmitting power of mobile station control procedure of the present invention;
Figure 12 illustrates the flow chart that uses another kind of base station power control procedure of the present invention.
At first with reference to figure 1, shown in the figure with the block diagram of the CDMA reverse channel architecture of a kind of prior art of reference number 10 expressions.This is the design drawing of a mobile radio station transmitter.Signal to be sent is received by square frame 11.In square frame 11, a frame quality indicator is added in this signal.Then, at square frame 12, add the end bit.Subsequently, at square frame 13, this signal is carried out convolutional encoding and at square frame 14, carries out the code element repetition.Then, square frame 15 data are modulated by alternation sum square frame 16.
Then, utilize a data subframe randomizer 17 to select in the power control group which and will be used for the transmission of this signal.With reference to figure 2, this illustrates the matrix of the power control group of representing with reference number 29 of dividing with speed.In this example, every frame has 16 logic power control groups (PCG).When selecting the full rate transmission, all 16 PCG are used.When selecting the half rate transmission, only the PCG of half is used.As shown in the figure, employed half PCG does not divide with the PCG of even number or odd-numbered, the function of Here it is randomizer 17.It selects among 16 stand-by PCG 8 randomly.For 1/4 and 1/8 speed also is roughly the same; Randomizer selects 4 or 2 PCG to use for transmission respectively.Note that the employed power level of each PCG (height as this square frame is represented) is identical.With reference to figure 1, long code generator 18 provides a signal to blender 19 again, and this signal is with combined from the output of data burst randomizer 17.The signal that obtains thus is divided into I and Q component by division; By mixing and up conversion with the 1.2288MHz signal; In delayer 23, postpone Q signal.Then, this I and Q component are filtered in filter 22 and 24 respectively; Mix mutually with the cosine and the sine of a signal psi respectively again.Again, these two signals merge in summer 27, so that signal to be sent to be provided.
Detailed description for the operation of transmitter shown in Figure 1 can find in the beginning of the 6.1.3 of TIA/EIA/IS-95 joint.
Fig. 3 shows the block diagram of CDMA forward channel structure with reference number 30.Channel architecture 30 receives signal to be sent, and by roughly handling with the identical process that Fig. 1 describes.Signal to be sent is modified by adding frame quality indicator 31 and tail coding 32.This signal interlocks by convolutional encoding, code element repetition and piece at square frame 33-35 and is further processed.Subsequently, the output of piece interleaver 35 mixes mutually with the long code that long code generator 37 produces, and is extracted in withdrawal device 38, so that it is reduced to 19.2ksps (per second thousand symbols) from 1.2288Mcps (per second million characters).
Then, mixed signal is imported into multiplexer (MUX) 39, and it and power control bit are multiplexed there.Multiplexer 39 is timed to 800Hz by the long code that has been extracted in withdrawal device 40.MUX 39 is used for shrinking (puncture) data flow and power control bit is inserted in the signal to be sent.
Then, this signal is separated, and in adder 41 with an I channel PN (pseudo random number) addition, in adder 42 with a Q channel PN (pseudo random number) addition.These two signals that obtain thus are filtered in filter 43 and 44 respectively.Filter 43 mixes with the cosine and the sine of signal psi respectively in blender 45 and 46 mutually with 44 output.The signal that draws thus is added together in summer 47, so that signal (S (t)) to be sent is provided.
When this signal is moved the station and receives and processed; Power control bit is discerned; In view of the above, mobile radio station is adjusted its power.
With reference to the flow chart of figure 4, the method for the power controlling that use a kind of prior art base station of briefly representing with reference number 50 shown in the figure.In step 51, when the base station receives PCG, method 50 beginnings.In practical operation, PCG is the whole of the signal that received by this base station during a specific period, no matter it be send by a specific mobile radio station or from some other sources transmission.In step 52, to the first that is received, promptly a PCG analyzes then, with estimated energy (i.e. the power level of Jie Shouing).
Then in step 53, this Energy Estimation and a threshold value (E
s) compare.If should estimate to surpass E
s, then in the transmission next time of mobile radio station, inserting a downward power control bit in step 54.If should estimate not surpass E
s, then in the transmission next time of mobile radio station, inserting a upwards power control bit in step 55.The transmission content that will contain power control bit then sends to mobile radio station.
Fig. 5 briefly shows a kind of method of the power controlling of being used by the prior art mobile radio station with reference number 60.When once sending when being received by this mobile radio station, method 60 begins in step 61.In step 62, analyze this signal, with the power control bit that recovers to send by the base station.In step 63, the mobile radio station response determines by the PCG pulse train of its transmission whether this power control bit sends.As mentioned above, if mobile radio station just sends with a speed that is lower than full rate, then not every PCG uses.In this case, the power control bit from the base station may be the result of the obsolete PCG of this mobile radio station.If mobile radio station does not use PCG, then should not proofread and correct its power according to base station measurements.Owing to grasped the propagation delay time, mobile radio station has just had the anticipatory knowledge of the PCG that is associated with power control bit.If power control bit is the response to used PCG, then adjust its power according to instruction at step 64 mobile radio station.If power control bit is not the response to used PCG, then this power control bit is left in the basket, and method 60 finishes in step 65.
With reference to figure 6, briefly a kind of matrix of dividing power control group according to transmission rate is shown among the figure with reference number 68.Exist between the matrix of Fig. 2 and this figure 2 different.The firstth, the present invention has used each PCG with all transmission rates.This is that redundant transmission by data realizes.For example, PCG1 is transmitted twice when half rate, is 1A for the first time, is 1B again.This just provides a kind of time diversity that can be used by receiver to improve the quality.Owing to time diversity makes E
s/ N
o(energy per bit/noise) is improved, thereby causes the improvement of capacity.Shown in matrix 68 and represented by each square frame height, the transmission of half rate PCG is in the half-power of full rate.The gross energy no change that consequently in cdma communication system, transmits, and quality has improved.
Fig. 7 briefly illustrates the method flow diagram that utilizes a kind of base station power control procedure of the present invention with reference number 70.In step 71, when the base station receives PCG, in step 72, estimated energy.Then, in step 73, this is estimated to compare with first threshold.This first threshold is high threshold, and will be and the relevant threshold value of full rate transmission, if this estimated energy then will be provided with three power control ratios specially for downward control bit (1,0,0) in step 74 above this threshold value.When mobile radio station receives this many power rate control command, it will control the power of its transmission downwards, and irrelevant with transmission rate.If should estimate to surpass this first threshold, then it and second threshold ratio in step 75.The threshold value of using when this second threshold value will be the half rate transmission.If should estimate to surpass this second threshold value, then step 76 should many power rate control command be set to (0,1,0).This order military order half, 1/4 and 1/8 rate transmitter are controlled transmitted power downwards and are made the full rate transmitter upwards control its transmitted power.In step 77 and 78, process 70 continues to set at the 3rd threshold value (1/4 speed rates), and in step 79 and 80, sets at the 4th threshold value (1/8 speed rates).If none is exceeded these two threshold values, then be set to (0,0,0) in many power rate of step 81 control command.When this order is received by mobile radio station, it will upwards control its transmitted power, and irrelevant with transmission rate.Then, in step 82, this power control command is inserted into next time in the transmission of mobile radio station, and is sent out away in step 83.
Fig. 8 briefly illustrates the flow chart of the Poewr control method that utilizes mobile radio station of the present invention with reference number 90.Method 90 is in step 91 beginning, received signal.Then,, handle this signal, to recover this power control command in step 92.Then, in step 93, method 90 is estimated this power control command, to determine obtaining the corresponding action that speed will be taked with it.Subsequently, in step 94, this mobile radio station is adjusted its power according to the instruction of this power control command, in step 95, this process when receiving next signal till and finish.
Thereby this method can make the operator avoid using the related variety of issue of duty cycle of burst by carry out continuous duty cycle with the power that reduces.In addition, because the E that the transmission time diversity provides repeated signal thereby obtains
s/ N
oCause the improvement of capacity.
With reference to figure 9, this figure briefly illustrates the block diagram that uses a kind of CDMA reverse channel architecture of the present invention with reference number 100.As prior art, signal to be transmitted receives at square frame 111, in square frame 111, a frame quality indicator is added on this signal.Then, at square frame 112 tailing bits.At square frame 113, to this signal convolutional encoding; With carry out code elements at square frame 114 and repeat.Then, these data are interlocked (115) and modulate (116).
In present design, because all PCG are used to all transmission rates, so need not randomizer.For this reason, the signal that is produced by modulator 116 is directly inputted to blender 119, there this signal with mix from the long code of long code generator 118.
Signal from blender 119 is divided into I and Q component; By with the signal mixing up conversion of one 1.2288 MHz; With in delayer 123, postpone Q signal.Then, in filter 122 and 124, I is become component filtering with Q respectively; And mix mutually with the cosine and the sine of signal psi.Then, two signals are incorporated into together in summer 127.
Signal from summer 127 is amplified by an adjustable amplifier 129 subsequently.Adjust according to its transmission rate pair amplifier 129.For full rate, this signal will be exported with total power.For half rate, this power will be as half-power represented in the matrix of Fig. 6.
With reference to Figure 10, this figure briefly illustrates a kind of block diagram of CDMA forward channel structure with reference number 130.Channel architecture as shown in Figure 3 is such, and this signal is by adding frame quality indicator 131 and tail encoder 132 has made modification of signal to be sent.Repeat by convolutional encoding, code element and piece is staggered is further handled at square frame 133-135.Subsequently, the output of piece interleaver 135 mixes with the long code of generation in the long code generator 137, and is extracted in withdrawal device 138, so that it is reduced to 19.2ksps (per second thousand symbols) from 1.2288Mcps (per second million characters).
Then, the signal that has mixed is input to multiplexer (MUX) 139, and is multiplexed with four power control bits there.Multiplexer 139 is timed to 800Hz by the long code that has further been extracted in the withdrawal device 140.MUX139 is used to make data flow contraction (puncture) and power control bit is inserted in the signal to be sent.Contraction forward link with four bits does not have tangible influence to the downlink quality performance.Current IS-95 down link use a kind of speed equal with 800bps (bps) 1/2 convolution code of shrinking.This speed with 0.522 is corresponding.In this suggestion, it is 0.570 that a kind of speed equals will cause speed with 1/2 convolution code that 2400bps shrinks.Another kind of interchangeable scheme is to utilize control channel such as SACCH (control channel that slow phase closes) transmission rate information.The another kind of method that reduces effect of contraction is to reduce the quantity of tail bit, reduces to 6 bits from 8 bits.
Figure 11 and 12 shows another embodiment of the communication system of utilizing the inventive method.Figure 11 briefly illustrates the flow chart of the method for using mobile radio station of the present invention with reference number 150.It sends sequence to method 150 in step 151 beginning.In step 152, first frame is processed with first transmission rate that sends, and is stored in step 153.Then, in step 154, second frame is processed with second transmission rate.In step 155, a designator of this second transmission rate is inserted in first frame, and send this frame in step 156.Then, in step 157, by inserting each designator of the transmission rate that sends subsequently, this method is proceeded.
Figure 12 briefly illustrates the flow chart of the method for using base station of the present invention with reference number 160.In step 161, when receiving signal, method 160 beginnings.In step 162, receive first frame.In step 163, utilize designator to determine second transmission rate.In step 164, when receiving second frame, estimate the power of this second frame, and in step 166 and the threshold that is used for second transmission rate.Then, can determine a power control command, and in next base station transmits, it be turned back to mobile radio station.
In view of the above, now provide a kind of method of operating, it allows to use continuous signal with any transmission rate by for using a plurality of energy thresholds with more low-yield level than lower rate transmissions.
Though now described the present invention in conjunction with specific embodiment, it is conspicuous that those skilled in the art can make various replacements, modification and modification according to description above.In view of the above, intention has comprised various replacements, modification and the modification that all are above-mentioned in claims.
Claims
Modification according to the 19th of treaty
1. the method in order to power controlling in cdma communication system is characterized in that, said method comprising the steps of:
Handle (152) send to the continuous signal of base station from mobile radio station with first transmission rate first frame;
Described first frame of described continuous signal is stored in the mobile radio station;
Handle (154) send to the continuous signal of described base station from described mobile radio station with second transmission rate second frame;
In first frame of described continuous signal, insert a designator of described second transmission rate of (155) second frames, to be used to control the power of described cdma communication system; With
Send described first frame of (156) described continuous signal.
2. according to the method for claim 1, it is characterized in that, further may further comprise the steps:
Receive described first frame of (162) described continuous signal in the base station;
According to the described designator in described first frame, determine (163) described second transmission rate;
Receive described second frame of (164) described continuous signal in described base station;
Estimate (165) described continuous signal described second frame be received power level; With
Described second frame described is received power level compare with the threshold power level of described second transmission rate (166).Statement according to the modification of the 19th of PCT
World Intellectual Property Organization's international office
Switzerland, Geneva 20, Ge Lunbeici 1211, and triumphant bright 34
Mr. executive officer:
The current modification is to submit in retrieval report dispatch day (on September 4th, 1996) two months.Please delete the 12-14 page or leaf, replace with the replacement page or leaf that this paper is appended.
Former claim 1-8 is deleted entirely.
Former claim 9 has been modified and has renumberd to new claim 1, has wherein stipulated " storage is carried out in mobile radio station ", has also stipulated " indicating device is used to control the power of cdma communication system ".
Former claim 10 renumbers and is new claim 2.
In search report, point out former claim 1-10 be subjected to people such as English United States Patent (USP) 5,528,593 influence and do not have novelty.The patent document of English is not described the method for a kind of indication of second transfer rate being inserted first frame, has not described the step that described definite second transmission rate of claim 2 forms first frame yet.
Applicants such as the Ghosh of Motorola Inc.
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